Bonding (Polyatomic Ions) Guided Notes 4a Bonding (Polyatomic Ions) *you NEED your Polyatomic Reference Sheet to understand where the names are coming from*

Go with this example… Pretend Mrs. Shorette is a CATION (has energy/electrons to GIVE). She has 1 valence electron because she is from Group 1. Rancho High School is an ANION (needs to TAKE electrons to be stable). Rancho needs 2 valence electrons (two sets of classes) because they are from Group 16. Mrs. Shorette cannot make an IONIC BOND with Rancho High School’s needs. Welcome back Chemistry classes! Come back home (room 1009) on Monday! 

What blue color means Throughout the slides you will see BLUE text. This text is additional information. You may add this information to your notes if it will help you!

What are polyatomics? Polyatomics: ions made of a __groups of atoms__ Example: ammonium __ (NH4) phosphate__(PO4)3- Hint- we find out the names of the (polyatomics) by looking at our Reference Sheet

How are polyatomics used in ionic compounds? Some __can lose/give__ electrons like a metal and become a __cation__ Example: ammonium (NH4)+ Most __will take__ electrons like a nonmetal and become an __anion__ Example: phosphate (PO4)3-

How do you determine the formula using polyatomics? Cross-down method (we find the charges of the polyatomics by looking at the Reference Sheet) (NH4)1+ O 2- _(NH4)2O_ (NH4)1+ We find the 1+ on the Reference Sheet O 2- Like before, we use the Group # to tell us that Oxygen NEEDS to TAKE 2 more valence electrons to be stable/complete

Continued Example Na+ (PO4) 3- __Na3(PO4)__ Na 1+ Sodium is in Group 1 and wants to GIVE away its 1 valence electron (you can just put a + to represent 1+) (PO4)3- We find the 3- on the Polyatomic Reference Sheet

How do you name these compounds? Positive ion is __1st__ Negative ion is __2nd__ “ide” ending __not used_ if elements are in brackets, then see Reference Sheet Note- Polyatomic name replaces the original ending.

Example (for naming) Sodium phosphate: Na3 (PO4) Na3 is Sodium (PO4) because it is in parenthesis we look at our Reference Sheet and find the name

Check for Understanding *Use your flow chart on the Reference Sheet* What is the name of Mg(SO4) _Magnesium _ _Sulfate_ What is the name of (NH4) Cl _Ammonium_ _Chloride_

Add to the bottom of your notes: Anytime you see ( ) they represent a polyatomic ion= check your table for their charge